Papa John's shares fell by as much as 5.9% Wednesday after the pizza chain's founder confirmed a report that he had used the n-word back in May, CNBC reports.

John Schnatter was on a conference call with a marketing agency at the time, according to the Forbes' report published Wednesday; the call was meant as a role-playing exercise to help Schnatter avoid future public relations messes like the one last year when he blamed the NFL's national anthem kneeling controversy for declining pizza sales.

During the call, sources say, Schnatter attempted to downplay his NFL comments by noting that "Colonel Sanders [of KFC] called blacks n-----s" and never faced backlash for it.

Schnatter, who recently stepped down as CEO of Papa John's but is still closely tied to the brand's image, also reportedly talked about growing up in Indiana, where black people were sometimes dragged from trucks until they died, in an apparent attempt to convey his dislike for racism.

Instead, many on the call were offended, and the agency's owner moved to terminate its contact with Papa John's. "News reports attributing the use of inappropriate and hurtful language to me during a media training session regarding race are true," Schnatter told Forbes.

"Regardless of the context, I apologize. Simply stated, racism has no place in our society." A Papa John's rep told CNBC the company "condemns racism and any insensitive language, no matter the situation or setting."